Chuck



Jan. 22, 1952 F HERRMANN 2,583,264

CHUCK Filed Aug. 20, 1946 Patented Jan. 22, 1952 Friedrich;V Heumann, Rorschach, Switzerland,

assignorf` to Rigid Limited, Rorschacherberg,

Switzercland:A

Applicatineugst zo, 194e-,V serai No. 691,776 lnr Switzerland August 2.7, 119452 2 Claims.

inventien relates4 tof, :lmprcrvements in chucks; teclee-plates. mandrels/zeand; like removable mtaryworkrand tookholders.. r I

Chucks: adapted! in the mannerrof as, bayonet V type tangandfsocket fastener-aren known.y in. the

art; Sucht-knownholders; l-ioweven:possess'A the disadvantage, thatainl rough `liandlingas"is usual in theaverage: short, the strut.,engagedin the groove isi Worn' down. Further,- such known holders require grooves adapted: for; toolszwhich: either areY left-cutting or right-cutting or; left-spiraled or-rightrspiraled, i; e.; oppositefhand tools reduire different chucks; or holders;-` and: thus trade tools which are. not provided; with. such grooves, cannotlbe used.V

Suche-,inconveniences and disadvantages are eliminated by thechuck or holder according to the, present invention. byu disposing onnthe tool spindle at equalv angular" spa-cings, ka plurality. of

clamping. devices which in oneposition` graspv a tool-holder to be held fasti or, thextool respectivelyffrom behind and-release same in the other position, so as to permit of speedily exchanging the' tool.

One.` embodiment of.; the; invention is illustrated. by' wayo examplevinthe drawings, in which Eig; l;y is; an axial sectionfofl a first form, on the. line I-I ofV Fig. 2,

Eig; 2 a cross-section on the line II-fII and, pari-,lyon lineIIa-Ia of-v Fig.. 1;, and` Fig. 3 a partial section on line III-IIIiLo Fig.. l. In the example accordinggtov Figs, 1 3; av socket 2l is disposed on the. end of the milling spindle I and secured againsty turning:V relative,v to, the lat.- terfby means of. twov diametri'cally' opposed dri-ver blocks 3 whichA are secured: to the spindle I by-a capwscrew 4 each and engaged in recesses of; the spindle IL andof; the socket 2. A screwl` each is disposedu in .the threaded bores; 550i; the. spindlee spaced' at 90 from eachotherfandcwacting .with a-.clamping sleeve; 1'; A springl washer l0. is dis',- posed onscrew 6 intermediate of a nut Bwhichz is mounted on the screwv and' heldby a pin 8 andthe clamping sleeve l,V pushing the latter up.. against the head H of Ythe screw 6.V so that the latter upon rotation tends to take the sleeve l along. with it. The turning of the latter,A how-V ever,A is limited to a SOP-range by virtue of a stop pinv l2 secured in thespindlel, in that the nib I3 of pin I2 coacts with abutment faces I4 (Figgf) of a sector-shaped recess of the clampingsl'eeve 1;'. VThe;latter;connniisesrtwo cams 15,/ l. and' the socket:v 2; comprises; a; longitudinal passage Irl.' sothat: in the. clamping; position.: shownin Egezby tullxlines. thecam's l-;5.. ,Ia6 grasp hehindelamping;

facesfoi; socket El; which in the sleeve-position incheatedv in Eig. Zbyl dash-and -dotglines the cams may pass; throughthe passage H so tl'iatl the socket. 2 Vin such positionis released forf removal. For thepurpose of turning screw 5 itsfhead H is provided with a hexagonal recess I8 to beengaged byl a hexagonal socket wrench 19.

When slacking the screw 6 by means of the socketwrench i9, `a slight runn-irvig.Y slack; isset up at once, which permits of turning the clamping sleeveV 'l'. The latter thus; at. once -is turnedfrom; the. clamping position through 90.57 intothe slackposiftion, at the same time being axial-ly` displaced in correspondencewith the; pitch ot screw 6, e. g.. by 0.5mm. atapitch of- 2 mm., The screw- 6, after having turned the clamping sleeveE-lf by 90-, may be slacked further still, afurther turning of sleeve l being prevented by the lstop pin H2,` but thesleeve being further displaced axially- Whenall the four 'sleeves' 'l thusV have been,slackedgr the, chuck socket 2 may be readily taken off the vmilling spindle head.

When, in securing1 the socket 2. the-screws ,6 are tightened, the sleeves: 'lA are at once turned from theslack-posi-tioninto@ the clamping position. When,` tightening up: the screws e still; further, the socket 2 isclamped fast on to the plane front-faceof the milling spindle soA that, after, tightening up all the four screws 6, the socket? is securelyr anchored.

Since the sleeves Thaveto: be turned through 905 only for opening andslacking and are axially displaced thereby in correspondence with the pitch of the screw 6 (e. g. by 05 mm. at a2 mm.- pitch), the clamping and slacking is quickly performed, Slight diierences o dis-tance between the bearingshoulder of sleeve l: on lsocket 2 and the bearing face of the latter on the front-face `ofi the, milling spindle l. are-,oi no importance.

boresI `to toothed pistons Eil are providedi in: theL socket 2,l intermediate of "the clampingnsleeves l. Each piston fZ'l is provided with external teethl engagedl -by the-'internaltooth rim 2-2- of a threaded sleeve 23:.` The: latter lsY providedywithfthreads: 2:4; and at alias a sliding fit onthe; socket. 2. When turning sleeve 23, all thev four pistons 2U are simnlfaneonsly turned, i.. e; a slight turning of sleeve 23 is sufficient to produce;` egg., a 90rotation of the pistons: 2li. "Anfaxle-pinv Z-tf'is mounted' in. the bore-fof each -pistonZlL ,and` at one end is nro-- vided `with a clamping cairl- 2l", while at theother end'a nut '281' is mounted-thereonto, secured by a pin "2995A compression spring# 3;V at oneV end abuis-against the'said nut'f, and` at thevotherend, against a shoulder 3l of the piston 20. The compression spring 30 forces the clamping cam 21 against the end of toothed piston 20 so that the axle pin 26 is carried along by friction with the cam 21 when the piston 20 rotates. The clamping cam 21 is adjustable in two positions, i. e. into the clamping position shown by full lines in Fig. 2, wherein the further rotation of the cam 21 is limited by a dog 32, and in the slackposition shown by dash-and-dot lines in Fig. 2,l

which latter position is limited by the abutment of clamping cam 21 in a recess of the threaded sleeve 23. When the ring 23 is turned, the toothed piston '20 is rotated by means of the gear teeth 2l, 22 and by this means the clamping cam 21 can thus be turned from one end position to the other. Upon further rotation of the ring 23 the clamping cam will not be carried any further because of the dog 22; however, it will be moved axially. Further a compression spring 33 engages the piston 2U, pushing the latter, to-j getherwith the clamping cam 21 outwardly against an inner face 34 of the sleeve 23.

The latter further is provided with recesses 35 on its periphery, adapted to be engaged by the round end 36 of socket wrench I9, so as to permit of turning the sleeve 23 as is required for slacking and clamping the cams 21.

Further, the sleeve 23 is provided with four recesses 31 adapted to be engaged by a securing spring latch 38 which is iixedly attached to the socket 2 by screw 39 and which serves for adjusting the sleeve 23 so that the passage openings provided therein for the socket wrench I9 may be broughtto register with the passage openings disposed in the socket '2 or, respectively to the screws 6 when the latter upon tightening or slacking the socket 2 have to be turned by means of the socket wrench I9. The securing spring 38 is of such strength as not to impair the turning of sleeve 23.

A protective ring 40, readily rotatable by hand, is mounted on the front-face of the threaded sleeve 23, and is held by a retainer ring 4I provided with a conical inner bore. The ring 4I is secured to the sleeve 23 by screws 42. The protective ring 46 is provided with four passage openings for the socket Wrench I9. The said latter openings may be aligned with the passage openings in the sleeve 23 by pressing a ball 43, influenced by a spring 44, into an index opening 45 of the protective ring 40. When the socket 2 is fastly secured by tightening up the screws 6, the protective ring 40 is brought into an intermediate position wherein it blocks the passage openings of the sleeve 23 so that, during machining, lings or chips are prevented from entering into the socket 2.

The socket 2 described serves for grasping a socket inset 46 provided with an external conical face 41 which fits the internal conical face of the milling spindle I. The inset 46 further is provided with two cylindrical external tting faces 48, 49 corresponding with internal tting faces of the socket 2, thus attaining an additional centering of the socket 2 and the inset 46. The latter, further, is provided with a front-face shoulder D with which the camming faces 5I of the cams 21 co-act so that the inset sleeve 46 is pressed fastly into the internal conical face of the milling spindle I in the clamping position of the cams 21,. The inset 46 is provided with an"internal conical face 52 wherein a tool 53, e. g. a milling tool, a twist drill and the like may be inserted and held fast, e. g., by a screw 54, whereby clamping tongues also, of course, might be used. The inset sleeve 46 is exchangeable and a plurality thereof is kept in stock, provided with different-size internal conical faces so as to permit of grasping different tools. The positive drive of the inset 46 is assured by the key 55 (Fig. 2). When taking off the inset sleeve 46, thethreaded sleeve 23 1s turned slightly counter-clockwise l (Fig. 2) to provide a slight displacement between the shoulder 50 on the inset sleeve 46 and the camming faces 5I of the cams 21 giving rise to an engagement of the latter by the toothed pistons 20 and their turning through approximately from the clamping position shown in full lines into the slack-position shown in Fig. 2 by dash-anddot lines. The .sleeve insets 41 now may be readily Withdrawn from the socket 2. Although a very slight turning only of the threaded sleeve 23 is necessary for coercively and simultaneously rotating the four tightening-down cams 21, the slack or play between the shoulder face 50 of" the sleeve inset 46 and the underside 5I of the clamping cams 21, becomes greater, according to the thread-pitch on the sleeve 23, when further turning the latter. In other Words, it is not necessary to turn the sleeve 23 within definite limits, which fact permits of fastly securing different sleeve insets 46, the shoulder face 50 of which is not accurately located equal relative to the external conical face 41.

When inserting a new sleeve v inset 46, the threaded sleeve 23 must be turned clockwise (Fig. 2) for the purpose of securing same. All the four clamping cams 21 then at once and simultaneously are turned from the open or slack position shown by dash-and-dot lines, into the hold-down position, and at the same time displaced somewhat axially. Upon further turning the threaded sleeve 23, the clamping cams 21 only are displaced axially to the left (Fig. l), their undersides 5I acting upon the shoulder-face 50 of the sleeve inset 46 until the latter is clamped fast in the socket 2.

It will be readily seen that a sleeve inset 46 may be exchanged much quicker than the socket 2. An exchanging of the latter also is less frequent in operation, that the adjustment of the threaded sleeve 23 relative to the socket 2, required for introducing the socket wrench I9, and the loosening of the four screws 6 does not often have to take place.

Since the socket in such a chuck is secured without the aid of tie rods, it is not necessary to climb on top of the machine or to walk about same. When using tie rods, as known in the art, one always had to look for proper intermediate rings, which search required quite some time, and which, now, is eliminated. Further, it is no longer necessary to strike the tools loose, which is quite 'some nuisance, since now the outside conical face of the sleeveinset is being automatically slacked.

A substantial improvement of the chuck described urther resides in the fact that, aside of the socket wrench and the sleeve insets, no loose parts are required for clamping or slacking the tools, thus saving much time, since less parts are liable to get lost and have to be looked for. Further, there is no risk of interchanging the parts inter se.

I claim: 4

l. InV a chuck and tool spindle assembly, a socket secured to the tool spindle, a plurality of rotatable and axially movable hollow pistons axially mounted within said socket and equally spaced around the axis of the spindle, said pistons being provided with external gear teeth. a threaded sleeve screwed on an external threaded surface of said socket, said sleeve having an inf ternal face extending transversely to the axis of,Y

the spindle, an internal gear rim on said sleeve in engagement with the gear teeth of all said pistons, a plurality of clamping cams each rotatably mounted in one of said hollow pistons and in frick able follow pistons equally spaced within said zo socket around the axis of the spindle, a threadgzgl'd sleeve engaged on the external threaded surface of said socket, said sleeve having an internal f e extendin transversely to the axis of the spind means operatively connecting said sleeve and said; follow pistons to rotate said pistons about their axis upon rotation of said sleeve, a plurality of clamping cams each rotatably mounted in one of said pistons and frictionally engaged therewith, whereby upon rotation ofsaid sleeve said pistons are turned and cause,v said clamping cams to simultaneously turn into tool locking or tool releasing position, and means tending to urge the clamping cams towards said transverse face of said sleeve whereby said cams are axially moved when turning said sleeve for releasing the tool.

FRIEDRICH HERRMANN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,904,641 Archea Apr. 18, 1933 FOREIGN PATENTS Number Country Date 424,999 Great Britain Mar. 5, 1935 OTHER REFERENCES Tool Engineering, pages 797 and 798, Nov. 17, 1921, Figs. 252 and 254. 

